mystery

With tens or even hundreds of billions of potentially habitable planets within our galaxy, the question becomes: are we alone?

Many scientists and commentators equate “more planets” with “more E.T.s”. However, the violence and instability of the early formation and evolution of rocky planets suggests that most aliens will be extinct fossil microbes.

Just as dead dinosaurs don’t walk, talk or breathe, microbes that have been fossilised for billions of years are not easy to detect by the remote sampling of exoplanetary atmospheres.

In research published [PDF] in the journal Astrobiology, we argue that early extinction could be the cosmic default for life in the universe. This is because the earliest habitable conditions may be unstable. […] Inhabited planets may be rare in the universe, not because emergent life is rare, but because habitable environments are difficult to maintain during the first billion years.

Our suggestion that the universe is filled with dead aliens might disappoint some, but the universe is under no obligation to prevent disappointment.

previously { Where is the Great Filter? Behind us, or not behind us? If the filter is in our past, there must be some extremely improbable step in the sequence of events whereby an Earth-like planet gives rise to an intelligent species comparable in its technological sophistication to our contemporary human civilization. }

Objective: Investigate whether the gut feelings of one person, as measured with an electrogastrogram (EGG), respond to the emotions of a distant person.

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This experiment suggests that some somatic feelings may be associated with perceptions transcending ordinary sensory capabilities. Of course, it would be imprudent to assume that all gut feelings necessarily contain intuitive information, as on occasion visceral sensations reflect little more than a bad burrito. But assuming that future studies can successfully replicate the present results, it may turn out that the “belly brain” is more perceptive than previously suspected, and that common reports of gut feelings having special intuitive qualities may have a basis in fact.

Penrose and many others argue from practical considerations, Godel’s theorem, and on philosophical grounds, that consciousness or awareness is non-algorithmic and so cannot be generated by a system that can be described by classical physics, such as a conventional computer, but could perhaps be generated by a system requiring a quantum (Hilbert space) description. Penrose suspects that aspects of quantum physics not yet understood might be needed to explain consciousness. In this paper we shall see that only known quantum physics is needed to explain perception.

Our best theories of physics imply we shouldn’t be here. The Big Bang ought to have produced equal amounts of matter and antimatter particles, which would almost immediately annihilate each other, leaving nothing but light.

So the reality that we are here – and there seems to be very little antimatter around – is one of the biggest unsolved mysteries in physics.

In 2001, Tanmay Vachaspati from Arizona State University offered a purely theoretical solution. Even if matter and antimatter were created in equal amounts, he suggested that as they annihilated each other, they would have briefly created monopoles and antimonopoles – hypothetical particles with just one magnetic pole, north or south.

As the monopoles and antimonopoles in turn annihilated each other, they would produce matter and antimatter. But because of a quirk in nature called CP violation, that process would be biased towards matter, leaving the matter-filled world we see today.

If that happened, Vachaspati showed that there should be a sign of it today: twisted magnetic fields permeating the universe. […] So Vachaspati and his colleagues went looking for them in data from NASA’s Fermi Gamma ray Space Telescope.

Sex in reptiles and fish is determined after conception, during embryogenesis, according to ambient environmental temperature. In contrast, in mammals and birds, sex is determined at conception.

In mammals, male births invariably occur slightly in excess […] with approximately 3% more males born than females. The reason for this discrepancy is uncertain as testicles produce equal numbers of X-bearing and Y-bearing spermatozoa. […]

We have shown that M/F varies in geographical space, exhibiting a latitude gradient, and that this gradient is different in Europe and North America, with more males born towards the south of Europe, compared with the North American continent where more males are born towards the north of the continent.

Other studies have also shown that M/F may vary with time. Several authors have shown that M/F has declined over the second half of the 20th century in various industrialised countries. These include Denmark, the United Kingdom, the Netherlands, Germany, Canada, the United States of America, and Finland. In contrast, M/F has been noted to have risen in Ireland over the same period. A non-significant rise in M/F has also been noted in Australia and Japan.

A wide variety of factors have been shown to influence the male to female ratio at birth, which invariably displays a male excess. […] It will be shown that stress, including stress related to political events, influences this ratio.

In a paper published in the journal Science, physicists reported that they were able to reliably teleport information between two quantum bits separated by three meters, or about 10 feet.

Quantum teleportation is not the “Star Trek”-style movement of people or things; rather, it involves transferring so-called quantum information — in this case what is known as the spin state of an electron — from one place to another without moving the physical matter to which the information is attached.

Many gardeners and horticulturalists seek non-chemical methods to control populations of snails. It has frequently been reported that snails that are marked and removed from a garden are later found in the garden again. This phenomenon is often cited as evidence for a homing instinct.

We report a systematic study of the snail population in a small suburban garden, in which large numbers of snails were marked and removed over a period of about 6 months. While many returned, inferring a homing instinct from this evidence requires statistical modelling. […]

Maximum likelihood techniques infer the existence of two groups of snails in the garden: members of a larger population that show little affinity to the garden itself, and core members of a local garden population that regularly return to their home if removed. The data are strongly suggestive of a homing instinct, but also reveal that snail-throwing can work as a pest management strategy.

Amoebas are puny, stupid blobs, so scientists were surprised to learn that they contain 200 times more DNA than Einstein did. Because amoebas are made of just one cell, researchers assumed they would be simpler than humans genetically. Plus, amoebas date back farther in time than humans, and simplicity is considered an attribute of primitive beings. It just didn’t make sense. […]

Before the advent of rapid, accurate, and inexpensive DNA sequencing technology in the early 2000s, biologists guessed that genes would provide more evidence for increasing complexity in evolution. Simple, early organisms would have fewer genes than complex ones, they predicted. […] Instead, their assumptions of increasing complexity began to fall apart. […]

Then molecular analyses did something else. They rearranged the order of branches on evolutionary trees. Biologists pushed aside trees based on how similar organisms looked to one another, and made new ones based on similarities in DNA and protein sequences. The results suggested that complex body parts evolved multiple times and had also been lost. One study found that winged stick insects evolved from wingless stick insects who had winged ancestors. […]

Perhaps the fact that people are stunned whenever organisms become simpler says more about how the human mind organizes the world than about evolutionary processes. People are more comfortable envisioning increasing complexity through time instead of reversals or stasis.

Popular hypotheses credit a primordial soup, a bolt of lightning and a colossal stroke of luck. But if a provocative new theory is correct, luck may have little to do with it. Instead, according to the physicist proposing the idea, the origin and subsequent evolution of life follow from the fundamental laws of nature and “should be as unsurprising as rocks rolling downhill.”

From the standpoint of physics, there is one essential difference between living things and inanimate clumps of carbon atoms: The former tend to be much better at capturing energy from their environment and dissipating that energy as heat. Jeremy England, a 31-year-old assistant professor at the Massachusetts Institute of Technology, has derived a mathematical formula that he believes explains this capacity. The formula, based on established physics, indicates that when a group of atoms is driven by an external source of energy (like the sun or chemical fuel) and surrounded by a heat bath (like the ocean or atmosphere), it will often gradually restructure itself in order to dissipate increasingly more energy. This could mean that under certain conditions, matter inexorably acquires the key physical attribute associated with life.

We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: ~8% of the men in this region carry it, and it thus makes up ~0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia ~1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior.

An international group of geneticists studying Y-chromosome data have found that nearly 8 percent of the men living in the region of the former Mongol empire carry y-chromosomes that are nearly identical. That translates to 0.5 percent of the male population in the world, or roughly 16 million descendants living today. […]

To have such a startling impact on a population required a special set of circumstances, all of which are met by Genghis Khan and his male relatives, the authors note in the study.

[Genghis Khan lived from 1162-1227 and raped and pillaged from Mongolia to the gates of Vienna. Once he captured a village or town, he would essentially kill all the men and rape the women.]

The Y-chromosome is passed on as a chunk of DNA from father to son, basically unchanged through generations except for random mutations.

These random mutations, which happen naturally and are usually harmless, are called markers. Once the markers have been identified, geneticists can go back in time and trace them to the point at which they first occurred, defining a unique lineage of descent.

In this particular instance, the lineage originated 1,000 years ago. The authors aren’t saying that the genetic mutations defining the lineage originated with Khan, who was born around 1162; they are more likely to have been passed on to him by a great great grandfather.

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The connection to Genghis Khan will never be a certainty unless his grave is found and his DNA could be extracted.

The location of the tomb of Genghis Khan has been the object of much speculation and research. The site remains undiscovered. […] According to one legend, the funeral escort killed anyone and anything that crossed their path, in order to conceal where he was finally buried. After the tomb was completed, the slaves who built it were massacred, and then the soldiers who killed them were also killed.

Antidepressants are often considered to be mere placebos despite the fact that meta-analyses are able to rank them. It follows that it should also be possible to rank different placebos, which are all made of sucrose. To explore this issue, which is rather more epistemological than clinical, we designed an unusual meta-analysis to investigate whether the effects of placebo in one situation are different from the effects of placebo in another situation.